如何使用.net生成验证码

这篇文章主要介绍"如何使用.net生成验证码"，在日常操作中，相信很多人在如何使用.net生成验证码问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答"如何使用.net生成验证码"的疑惑有所帮助！接下来，请跟着小编一起来学习吧！

先给大家看看效果图：

页面代码：

      
  
    
      
        
          验证码        
        
                  
        
                  
        
          换一张        
      
      
        
                  
      
    
  
  

后台代码:

/// 
    /// 登录    /// 
    ///     protected void LoginSubmits(object sender, EventArgs e)    {      CheckLogin();    }    #region 私有方法    #region    public static Boolean IsNotNull(Object str)    {      return !IsNull(str);    }    public static Boolean IsNull(Object str)    {      return str == null;    }    public static void Show(System.Web.UI.Page page, string msg)    {      page.ClientScript.RegisterStartupScript(page.GetType(), "message",        "");    }    #endregion    private void CheckLogin()    {      if (tbCheckCode.Text.Trim() == "")      {        Show(this, "验证码不能为空!");        return;      }      else      {        if (IsNotNull(Session["ValidateCheckCode"]))        {          if (tbCheckCode.Text.Trim() != Session["ValidateCheckCode"].ToString())          {            Show(this, "验证码填写不正确!");            tbCheckCode.Text = "";            return;          }        }        else        {          Show(this, "请刷新验证码！");          return;        }      }    }    #endregion  }}

生成验证码:

using System;using System.Drawing;using System.Text;using System.Web;namespace Web.TEXT{  public partial class VerifyCode : System.Web.UI.Page  {    public Encoding GB = Encoding.GetEncoding("GB2312");    protected void Page_Load(object sender, EventArgs e)    {      VerifyCode v = new VerifyCode();      v.Length = this.length;      v.FontSize = this.fontSize;      v.Chaos = this.chaos;      v.BackgroundColor = this.backgroundColor;      v.ChaosColor = this.chaosColor;      v.CodeSerial = this.codeSerial;      v.Colors = this.colors;      v.Fonts = this.fonts;      v.Padding = this.padding;      string code = v.CreateVerifyCode(); //取随机码      v.CreateImageOnPage(code, this.Context); // 输出图片      Response.Cookies.Add(new HttpCookie("CheckCode", code.ToUpper())); // 使用Cookies取验证码的值      System.Web.HttpContext.Current.Session["ValidateCheckCode"] = code;      //return checkCode;    }    #region 验证码长度(默认4个验证码的长度)    private int length = 4;     public int Length    {      get { return length; }      set { length = value; }    }    #endregion    #region 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改)    private int fontSize = 12;    public int FontSize    {      get { return fontSize; }      set { fontSize = value; }    }    #endregion    #region 边框补(默认1像素)    private int padding = 1;    public int Padding    {      get { return padding; }      set { padding = value; }    }    #endregion    #region 是否输出燥点(默认不输出)    private bool chaos = true;    public bool Chaos    {      get { return chaos; }      set { chaos = value; }    }    #endregion    #region 输出燥点的颜色(默认灰色)    private Color chaosColor = Color.LightGray;    public Color ChaosColor    {      get { return chaosColor; }      set { chaosColor = value; }    }    #endregion    #region 自定义背景色(默认白色)    private Color backgroundColor = Color.White;    public Color BackgroundColor    {      get { return backgroundColor; }      set { backgroundColor = value; }    }    #endregion    #region 自定义随机颜色数组    private Color[] colors =    {      Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown,      Color.DarkCyan, Color.Purple    };    public Color[] Colors    {      get { return colors; }      set { colors = value; }    }    #endregion    #region 自定义字体数组    private string[] fonts = {"Arial", "Georgia"};    public string[] Fonts    {      get { return fonts; }      set { fonts = value; }    }    #endregion    #region 自定义随机码字符串序列(使用逗号分隔)    private string codeSerial = "0,1,2,3,4,5,6,7,8,9";    // string codeSerial = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";    // string codeSerial = "殃,央,鸯,秧,杨,扬,佯,疡,羊,洋,阳,氧,仰,痒,养,样,漾,邀,腰,妖,瑶,摇,尧,遥,窑,谣,姚,咬,舀,药,要,耀,椰,噎,耶,爷,野,冶,也,页,掖,业,叶,曳,腋,夜,液,一,壹,医,揖,铱,依,伊,衣,颐,夷,遗,移,仪,胰,疑,沂,宜,姨,彝,椅,蚁,倚,已,乙,矣,以,艺,抑,易,邑,屹,亿,役,臆,逸,肄,疫,亦,裔,意,毅,忆,义,益,溢,诣,议,谊,译,异,翼,翌,绎,茵,荫,因,殷,音,阴,姻,吟,银,淫,寅,饮,尹,引,隐,印,英,樱,婴,鹰,应,缨,莹,萤,营,荧,蝇,迎,赢,盈,影,颖,硬,映,哟,拥,佣,臃,痈,庸,雍,踊,蛹,咏,泳,涌,永,恿,勇,用,幽,优,悠,忧,尤,由,邮,铀,犹,油,游,酉,有,友,右,佑,釉,诱,又,幼,迂,淤,于,盂,榆,虞,愚,舆,余,俞,逾,鱼,愉,渝,渔,隅,予,娱,雨,与,屿,禹,株,蛛,朱,猪,诸,诛,逐,竹,烛,煮,拄,瞩,嘱,主,著,柱,助,蛀,贮,铸,筑,住,注,祝,驻,抓,爪,拽,专,砖,转,撰,赚,篆,桩,庄,装,妆,撞,壮,状,椎,锥,追,赘,坠,缀,谆,准,捉,拙,卓,桌,琢,茁,酌,啄,着,灼,浊,兹,咨,资,姿,滋,淄,孜,紫,仔,籽,滓,子,自,渍,字,鬃,棕,踪,宗,综,总,纵,邹,走,奏,揍,租,足,卒,族,祖,诅,阻,组,钻,纂,嘴,醉,最,罪,尊,遵,昨,左,佐,柞,做,作,坐,座";    public string CodeSerial    {      get { return codeSerial; }      set { codeSerial = value; }    }    #endregion    //产生波形滤镜效果    #region 产生波形滤镜效果    private const double PI = 3.1415926535897932384626433832795;    private const double PI2 = 6.283185307179586476925286766559;    /**/    /// 
    /// 正弦曲线Wave扭曲图片（Edit By 51aspx.com）    /// 
    /// 图片路径    /// 如果扭曲则选择为True    /// 波形的幅度倍数，越大扭曲的程度越高，一般为3    /// 波形的起始相位，取值区间[0-2*PI)    ///     public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)    {      System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);      // 将位图背景填充为白色      System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp);      graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height);      graph.Dispose();      double dBaseAxisLen = bXDir ? (double) destBmp.Height : (double) destBmp.Width;      for (int i = 0; i < destBmp.Width; i++)      {        for (int j = 0; j < destBmp.Height; j++)        {          double dx = 0;          dx = bXDir ? (PI2*(double) j)/dBaseAxisLen : (PI2*(double) i)/dBaseAxisLen;          dx += dPhase;          double dy = Math.Sin(dx);          // 取得当前点的颜色          int nOldX = 0, nOldY = 0;          nOldX = bXDir ? i + (int) (dy*dMultValue) : i;          nOldY = bXDir ? j : j + (int) (dy*dMultValue);          System.Drawing.Color color = srcBmp.GetPixel(i, j);          if (nOldX >= 0 && nOldX < destBmp.Width            && nOldY >= 0 && nOldY < destBmp.Height)          {            destBmp.SetPixel(nOldX, nOldY, color);          }        }      }      return destBmp;    }    #endregion    #region 生成校验码图片    public Bitmap CreateImageCode(string code)    {      int fSize = FontSize;      int fWidth = fSize + Padding;      int imageWidth = (int) (code.Length*fWidth) + 4 + Padding*2;      int imageHeight = fSize*2 + Padding;      System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);      Graphics g = Graphics.FromImage(image);      g.Clear(BackgroundColor);      Random rand = new Random();      //给背景添加随机生成的燥点      if (this.Chaos)      {        Pen pen = new Pen(ChaosColor, 0);        int c = Length*10;        for (int i = 0; i < c; i++)        {          int x = rand.Next(image.Width);          int y = rand.Next(image.Height);          g.DrawRectangle(pen, x, y, 1, 1);        }      }      int left = 0, top = 0, top1 = 1, top2 = 1;      int n1 = (imageHeight - FontSize - Padding*2);      int n2 = n1/4;      top1 = n2;      top2 = n2*2;      Font f;      Brush b;      int cindex, findex;      #region 随机字体和颜色的验证码字符      for (int i = 0; i < code.Length; i++)      {        cindex = rand.Next(Colors.Length - 1);        findex = rand.Next(Fonts.Length - 1);        f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);        b = new System.Drawing.SolidBrush(Colors[cindex]);        if (i%2 == 1)        {          top = top2;        }        else        {          top = top1;        }        left = i*fWidth;        g.DrawString(code.Substring(i, 1), f, b, left, top);      }      //画一个边框 边框颜色为Color.Gainsboro      g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);      g.Dispose();      //产生波形      //image = TwistImage(image, true, 8, 4);      return image;    }    #endregion    //将创建好的图片输出到页面    public void CreateImageOnPage(string code, HttpContext context)    {      System.IO.MemoryStream ms = new System.IO.MemoryStream();      Bitmap image = this.CreateImageCode(code);      image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);      context.Response.ClearContent();      context.Response.ContentType = "image/Jpeg";      context.Response.BinaryWrite(ms.GetBuffer());      ms.Close();      ms = null;      image.Dispose();      image = null;    }    #endregion    #region 生成随机字符码    public string CreateVerifyCode(int codeLen)    {      if (codeLen == 0)      {        codeLen = Length;      }      string[] arr = CodeSerial.Split(',');      string code = "";      int randValue = -1;      Random rand = new Random(unchecked((int) DateTime.Now.Ticks));      for (int i = 0; i < codeLen; i++)      {        randValue = rand.Next(0, arr.Length - 1);        code += arr[randValue];      }      return code;    }    public string CreateVerifyCode()    {      return CreateVerifyCode(0);    }    #endregion  }}

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